The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventor(s), to the extent the work is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art, at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Light-emitting-diode (LED) dimming or modulation of LED intensity is typically implemented using modulation schemes that utilize an average duty cycle that is proportional to the desired dimming level in a fixed time-period. For example, modulation schemes such as pulse-width modulation (PWM), and pulse-amplitude modulation (PAM) are commonly utilized to achieve a desired dimming level of the LEDs.
However, PWM suffers from significant ham tonic generation at relatively low frequencies that causes electromagnetic interference (EMI), and is prone to flickering at low LED light intensities. Thus, in order to implement the PWM technique, intense filtering is typically required to remove the high frequency components. Moreover, in order to support high-resolution dimming (e.g., 14 bit dimming), high-resolution digital-to-analog converters (DACs) are required. The high resolution DACs typically occupy a large surface area on a chip and consume substantial amounts of power. Additionally, in implementing PWM/PAM, a high-resolution PWM timer is required to drive the DAC.
Accordingly, there is a requirement for a universal LED dimming interface that can be programmed to provide alternative modulation formats in addition to PWM and DC to overcome the aforementioned problems.